Strained silicon CMOS on hybrid crystal orientations

ABSTRACT

Methods of forming a strained Si-containing hybrid substrate are provided as well as the strained Si-containing hybrid substrate formed by the methods. In the methods of the present invention, a strained Si layer is formed overlying a regrown semiconductor material, a second semiconducting layer, or both. In accordance with the present invention, the strained Si layer has the same crystallographic orientation as either the regrown semiconductor layer or the second semiconducting layer. The methods provide a hybrid substrate in which at least one of the device layers includes strained Si.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/830,347, filed Apr. 22, 2004. This application is related toco-pending and co-assigned U.S. patent application Ser. No. 10/250,241,filed Jun. 17, 2003, and co-pending and co-assigned U.S. patentapplication Ser. No. 10/696,634, filed Oct. 29, 2003, the entirecontents of each of the aforementioned U.S. Applications areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to high-performance metal oxidesemiconductor field effect transistors (MOSFETs) for digital or analogapplications, and more particularly to MOSFETs utilizing carriermobility enhancement from surface orientation.

BACKGROUND OF THE INVENTION

In present semiconductor technology, CMOS devices, such as nFETs orpFETs, are typically fabricated upon semiconductor wafers, such as Si,that have a single crystal orientation. In particular, most of today'ssemiconductor devices are built upon Si having a (100) crystalorientation.

Electrons are known to have a high mobility for a (100) Si surfaceorientation, but holes are known to have high mobility for a (110)surface orientation. That is, hole mobility values on (100) Si areroughly 2×-4× lower than the corresponding electron mobility for thiscrystallographic orientation. To compensate for this discrepancy, pFETsare typically designed with larger widths in order to balance pull-upcurrents against the nFET pull-down currents and achieve uniform circuitswitching. pFETs having larger widths are undesirable since they take upa significant amount of chip area.

On the other hand, hole mobilities on (110) Si are 2× higher than on(100) Si; therefore, pFETs formed on a (110) surface will exhibitsignificantly higher drive currents than pFETs formed on a (100)surface. Unfortunately, electron mobilities on (110) Si surfaces aresignificantly degraded compared to (100) Si surfaces.

As can be deduced from the above discussion, the (110) Si surface isoptimal for pFET devices because of excellent hole mobility, yet such acrystal orientation is completely inappropriate for nFET devices.Instead, the (100) Si surface is optimal for nFET devices since thatcrystal orientation favors electron mobility.

Co-pending and co-assigned U.S. patent application Ser. No. 10/250,241,filed Jun. 17, 2003, provides an approach to fabricate CMOS devices onhybrid orientations wherein the pFETs are formed on a (110) surfaceorientation and nFETs are formed on a (100) surface orientation. Becausehole mobility is greater than 150% higher on (110) orientation than on(100) orientation, the performance of pFETs is greatly enhanced fromconventional CMOS technology. Despite the enhancement, the nFETs remainthe same as conventional CMOS.

In view of the above, there is a need for providing integratedsemiconductor devices that are formed upon a substrate having differentcrystal orientations that provide enhanced device performance for aspecific type of device. The enhanced device performance is required forboth nFETs and pFETs thereby improving upon the technology described inco-pending and co-assigned U.S. application Ser. No. 10/250,241.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a method ofintegrating semiconductor devices such that different types of devicesare formed upon a specific crystal orientation of a hybrid substratethat enhances the performance of each type of device.

Another object of the present invention is to provide a method ofintegrating semiconductor devices such that the pFETs are located on a(110) crystallographic plane, while the nFETs are located on a (100)crystallographic plane of a hybrid substrate.

A further object of the present invention is to improve the deviceperformance of nFETs and further enhance the device performance of pFETsusing a hybrid crystal orientated substrate that includes strained Si asan upper device layer in which nFETs and/or pFETs can be fabricated.

A still further object of the present invention is to provide a methodof fabricating a strained Si-containing hybrid substrate havingdifferent crystal orientations in which one device has bulk-likeproperties and the other device has SOI-like properties.

An even further object of the present invention is to provide a methodof fabricating a strained Si-containing hybrid substrate havingdifferent crystal orientations in which the devices formed thereon eachhave SOI-like properties.

These and other objects and advantages are achieved in the presentinvention by utilizing methods in which a hybrid substrate comprisingfirst and second semiconducting layers having different crystalorientations is first provided. After providing the hybrid substratehaving different crystal orientations, the substrate is subjected topatterning, etching and regrowth of a semiconductor layer. A strained Silayer can be formed before the patterning step such that the strained Silayer has the same crystallographic orientation as the secondsemiconducting layer and/or it can be formed after regrowth so that thestrained Si layer has the same crystallographic orientation as the firstsemiconducting layer. Following these steps, isolation regions can beformed and semiconductor devices can be formed atop the strainedSi-containing hybrid substrate.

In broad terms, the present invention provides a method of forming astrained Si-containing hybrid substrate that comprises the steps of:

providing a hybrid substrate comprising a first semiconducting layer ofa first crystallographic orientation, a buried insulating layer locatedon a surface of the first semiconductor layer and a secondsemiconducting layer of a second crystallographic orientation which isdifferent from the first crystallographic orientation located on saidburied insulating layer;

providing an opening the extends to a surface of the firstsemiconducting layer; and

regrowing a semiconductor material on said first semiconducting layer insaid opening, said semiconductor material having the firstcrystallographic orientation, with the proviso that a strained Si layeris formed overlying at least one of the second semiconducting layer orthe regrown semiconductor material, said Si layer having acrystallographic orientation that matches that of said underlying secondsemiconducting layer or the regrown semiconductor material.

In some embodiments of the present invention, the strained Si layer isformed within the opening atop a recessed regrown semiconductormaterial.

In other embodiments of the present invention, the strained Si layeroverlies the second semiconductor layer and is formed atop the secondsemiconducting layer prior to forming the opening within the hybridsubstrate.

In yet other embodiments of the present invention, the strained Si layeroverlies both the regrown semiconductor material and the secondsemiconducting layer. In those embodiments, a first strained Si layer isformed atop the second semiconducting layer prior to forming the openingwithin the hybrid substrate, and a second strained Si layer is formedatop a recessed regrown semiconductor material within said opening.

In still yet other embodiments of the present invention, the strained Silayer is formed atop a relaxed SiGe alloy layer that has been formed viaa thermal mixing process.

The present invention also provides a Si-containing hybrid substratecomprising

a hybrid substrate comprising a first semiconducting layer of a firstcrystallographic orientation, a buried insulating layer located on asurface of the first semiconductor layer and a second semiconductinglayer of a second crystallographic orientation which is different fromthe first crystallographic orientation located on said buried insulatinglayer;

a regrown semiconductor material located on a surface portion of thefirst semiconducting layer; and

a strained Si layer overlying at least one of the regrown semiconductorlayer or the second semiconductor layer, wherein said strained Si layerhas a crystallographic orientation that matches the crystallographicorientation of the underlying regrown semiconductor material or thesecond semiconducting layer.

In some embodiments, the strained Si layer overlies the regrownsemiconductor material only. In other embodiments, the strained Si layeroverlies the second semiconducting layer only. In yet other embodiments,strained Si layers overlay both the regrown semiconductor material andthe second semiconductor layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D are pictorial representations (through cross sectionalviews) showing processing steps of a first embodiment of the presentinvention.

FIGS. 2A-2D are pictorial representations (through cross sectionalviews) showing processing steps of a second embodiment of the presentinvention.

FIGS. 3A-3D are pictorial representations (through cross sectionalviews) showing processing steps of a third embodiment of the presentinvention.

FIGS. 4A-4E are pictorial representations (through cross sectionalviews) showing processing steps of a fourth embodiment of the presentinvention.

FIGS. 5A-5E are pictorial representations (through cross sectionalviews) showing processing steps of a fifth embodiment of the presentinvention.

FIGS. 6A-6D are pictorial representations (through cross sectionalviews) showing processing steps of a sixth embodiment of the presentinvention.

FIGS. 7A-7D are pictorial representations (through cross sectionalviews) showing processing steps of a seventh embodiment of the presentinvention.

FIGS. 8A-8E are pictorial representations (through cross sectionalviews) showing processing steps of an eighth embodiment of the presentinvention.

FIGS. 9A-9E are pictorial representations (through cross sectionalviews) showing processing steps of a ninth embodiment of the presentinvention.

FIGS. 10A-10F are pictorial representations (through cross sectionalviews) showing processing steps of a tenth embodiment of the presentinvention.

FIGS. 11A-11G are pictorial representations (through cross sectionalviews) showing processing steps of an eleventh embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention, which provides methods of fabricating CMOSdevices on a strained Si-containing hybrid substrate having first andsecond semiconducting layers of different crystal orientations, will nowbe described in greater detail by referring to the drawings thataccompany the present application. The drawings that accompany thepresent application illustrate the strained Si-containing hybridsubstrate only. Illustration of semiconductor devices, and trenchisolation regions within each of the drawings has been omitted forclarity. Despite this omission, the strained Si-containing hybridsubstrates shown in the drawings can contain semiconductor devices,i.e., CMOS transistors, atop the uppermost layers of the substrate andtrench isolation regions can be formed therein as well.

In the drawings, the final hybrid substrate has upper coplanar regionsof different crystallographic orientation. The coplanar regions could befor example, a second semiconducting layer and a strained Si layer;strained Si layer and a regrown semiconductor material; or a firststrained Si layer and a second strained Si layer. As stated above, eachupper region has a crystallographic orientation that differs from theother.

Reference is first made to FIGS. 1A-1D which illustrate a firstembodiment of the present invention. In this first embodiment (See FIG.1D), a strained Si layer 20 is located on a relaxed SiGe layer 18 thatis formed atop a surface of the second semiconducting layer 16 of hybridsubstrate 10. In the embodiment, the device that would be formed atopthe strained Si layer 20 would be SOI like since a buried insulatinglayer 14 is located there beneath. A regrown semiconductor layer 28 isformed after formation of the relaxed SiGe layer 18 and the strained Silayer 20 by patterning, etching and regrowth. Regrowth occurs on thefirst semiconductor layer 12 of the hybrid substrate 10 thus the regrownsemiconductor layer 28 has the same crystal orientation as the firstsemiconductor layer 12 of the hybrid substrate 10, while the strained Silayer 20 and the relaxed SiGe layer 18 have the same crystal orientationas the second semiconductor layer 16 of the hybrid substrate 10. Asshown in FIG. 1D, isolation is present in the structure in the form ofoptional spacers 27.

Referring to FIG. 1A, there is shown the hybrid substrate 10 that isemployed in the first embodiment of the present invention. The hybridsubstrate 10 comprises a first semiconducting layer 12, a buriedinsulating layer 14 located on a surface of the first semiconductinglayer 12, and a second semiconducting layer 14 located on a surface ofthe buried insulating layer 14. In accordance with the presentinvention, the first semiconducting layer 12 of the hybrid substrate 10comprises a first semiconducting material that has a firstcrystallographic orientation and the second semiconducting layer 16 ofthe hybrid substrate 10 comprises a second semiconducting material thathas a second crystallographic orientation which differs from the firstcrystallographic orientation.

The first semiconducting layer 12 of the hybrid substrate 10 iscomprised of any semiconducting material including, for example, Si,SiC, SiGe, SiGeC, Ge, GaAs, InAs, InP as well as other III/V or II/VIcompound semiconductors. Combinations of the aforementionedsemiconductor materials are also contemplated herein. The firstsemiconducting layer 12 may be unstrained, strained or a combination ofstrained and unstrained layers. The first semiconducting layer 12 isalso characterized as having a first crystallographic orientation whichmay be (110), (111), or (100). The first semiconducting layer 12 mayoptionally be formed on top of a handling wafer.

In some instances, the first semiconducting layer 12 is a bulk handlewafer, and its thickness is the thickness of a wafer.

The second semiconducting layer 16 is comprised of any semiconductingmaterial which may be the same or different from that of the firstsemiconducting layer 12. Thus, the second semiconducting layer 16 mayinclude, for example, Si, SiC, SiGe, SiGeC, Ge, GaAs, InAs, InP as wellas other III/V or II/VI compound semiconductors. The secondsemiconducting layer 16 may be unstrained, strained or a combination ofstrained and unstrained layers. The second semiconducting layer 16 mayalso include combinations of the aforementioned semiconductingmaterials.

The second semiconducting layer 16 is also characterized as having asecond crystallographic orientation, which is different from the firstcrystallographic orientation. Thus, the crystallographic orientation ofthe second semiconducting layer 16 is (100), (111), or (110) with theproviso that the crystallographic orientation of the secondsemiconducting layer 16 is not the same as the crystallographicorientation of the first semiconducting layer 12.

The thickness of the second semiconducting layer 16 may vary dependingon the initial starting wafer used to form the hybrid substrate 10.Typically, however, the second semiconducting layer 16 has a thicknessfrom about 10 nm to about 200 μm, with a thickness from about 50 nm toabout 2 μm being more typical.

The buried insulating layer 14 that is located between the first andsecond semiconducting layers (12 and 16) of the hybrid substrate 10 canbe an oxide, nitride, oxynitride or any combination of these insulatingmaterials. In some embodiments, the buried insulating layer 14 is anoxide.

The hybrid substrate 10 shown in FIG. 1A is formed utilizing a layertransfer process in which bonding is employed.

In some embodiments of the present invention, the hybrid substrate 10 isan SOI substrate having a thick BOX region, i.e., buried oxide. In suchan embodiment, the SOI thickness is from about 5 to 100 nm. In yetanother embodiment of the present invention, the hybrid substrate 10contains a thin BOX that is formed by semiconductor-to-semiconductor,especially Si-to-Si, direct wafer bonding. In this embodiment, the topSOI layer has a thickness from about 200 nm to about 2 μm, while the BOXhas a thickness of less than about 10 nm. In still yet anotherembodiment of the present invention, the hybrid substrate 10 contains athick BOX formed beneath a thick SOI layer. In that embodiment, the SOIlayer has a thickness from about 200 nm to about 2 μm, while the BOX hasa thickness of about 10 nm or greater. In this embodiment, the hybridsubstrate is formed by bonding at least one semiconductor wafer havingan insulator to another semiconductor wafer, which may or may not havean insulating layer.

The semiconducting layers (12 and 16) used in fabricating the hybridsubstrate 10 may include two SOI wafers wherein one of the wafersincludes the first semiconducting layer 12 and the other wafer includesthe second semiconducting layer 16; an SOI wafer and a bulksemiconductor wafer; two bulk semiconductor wafers which both contain aninsulating layer thereon; or an SOI wafer and a bulk wafer whichincludes an ion implant region, such as a H₂ implant region, which canbe used to split a portion of at least one of the wafers during bonding.

Bonding is achieved by first bringing the two semiconducting wafers intointimate contact with other; optionally applying an external force tothe contacted wafers; and then heating the two contacted wafers underconditions that are capable of bonding the two wafers together. Theheating step may be performed in the presence or absence of an externalforce. The heating step is typically performed in an inert ambient at atemperature from about 200° to about 1050° C. for a time period fromabout 2 to about 20 hours. More preferably, the bonding is performed ata temperature from about 200° to about 400° C. for a time period fromabout 2 to about 20 hours. The term “inert ambient” is used in thepresent invention to denote an atmosphere in which an inert gas, such asHe, Ar, N₂, Xe, Kr or a mixture thereof, is employed. A preferredambient used during the bonding process is N₂.

In the embodiment in which direct semiconductor-to-semiconductor waferbonding is employed, bonding is achieved at nominal room temperature(15° C.-40° C.). The surfaces of the two wafers used in this directbonding technique may be subjected to a surface treatment step in whichat least one, but preferably both, of the surfaces for direct bondingare converted into a hydrophilic or hydrophobic surface.

Hydrophobic surfaces can be achieved, for example, by utilizing a HF dipprocess such as disclosed in S. Bengtsson, et al., “Interface chargecontrol of directly bonded silicon structures”, J. Appl. Phys. V 66, p1231, (1989), while hydrophilic surfaces can be achieved by either a dryclean process, such as, for example, an oxygen plasma (See, S. Farrens,“Chemical free room temperature wafer to wafer bonding”, J. Electrochem.Soc. Vol 142, p 3949, (1995)); an argon high-energy beam surfaceetching, and/or a wet chemical oxidizing acid such as H₂SO₄ or HNO₃solution. The wet etching process is disclosed, for example, in M.Shimbo, etc. “Silicon-to-silicon direct bonding method”, J. Appl. Phys.V 60, p 2987 (1986).

In some embodiments, an additional annealing step is performed after thebonding to further increase the bond strength of the bonded wafers. Whenthe additional annealing step is employed, the annealing occurs in aninert ambient at a temperature from 100° to about 400° C. for a timeperiod from about 2 to about 30 hours. More preferably, and whenincreased bonding energy is required, the annealing step that occursafter bonding is performed at a temperature from about 200° to about300° C. for a time period from about 2 to about 20 hours. When an H₂implant is present, layer splitting occurs after bonding at the implantregion during a 350° C.-500° C. anneal.

In the embodiment where two SOI wafers are employed, some materiallayers of at least one of the SOI wafers may be removed after bondingutilizing a planarization process such as chemical mechanical polishing(CMP) or grinding and etching.

In the embodiment in which one of the wafers includes an ion implantregion, the ion implant region forms a porous region during bondingwhich causes a portion of the wafer above the ion implant region tobreak off leaving a bonded wafer. The implant region is typicallycomprised of H₂ ions that are implanted into the surface of the waferutilizing ion implantation conditions that are well known to thoseskilled in the art.

After providing the hybrid substrate 10 shown in FIG. 1A, a relaxed SiGealloy layer 18 is formed on a surface of the second semiconducting layer16 of the hybrid substrate 10 by utilizing a conventional epitaxialgrowth process. The structure including the relaxed SiGe alloy layer 18is shown, for example, in FIG. 1B. The thickness of the relaxed SiGealloy layer 18 may vary provided that the SiGe alloy layer 18 that isgrown is in a relaxed state. Typically, the relaxed SiGe alloy layer 18has a thickness from about 10 to about 2000 nm, with a thickness fromabout 50 to about 1000 nm being more typical.

Since the relaxed SiGe alloy layer 18 is epitaxially grown on a surfaceof the second semiconducting layer 16, the relaxed SiGe alloy layer 18will have the same crystallographic orientation as the secondsemiconducting layer 16.

After forming the relaxed SiGe alloy layer 18 atop the hybrid substrate10, a strained Si layer 20 is formed atop the relaxed SiGe alloy layer18. The structure including the strained Si layer 20 is also shown inFIG. IB. The strained Si layer 20 is formed atop the relaxed SiGe alloylayer 18 utilizing an epitaxial growth method.

The strained Si layer 20 has a thickness that is generally less than thethickness of the underlying relaxed SiGe alloy layer 18. Typically, thethickness of the strained Si layer 20 is from about 5 to about 50 nm,with a thickness from about 10 to about 20 nm being more typical. Thelevel of strain in the strained Si layer 20 is a function of the Ge molefraction of the SiGe alloy layer 18. A 20% of Ge is typically used.

Since the strained Si layer 20 is formed on a surface of the relaxedSiGe alloy layer 18, the strained Si layer 20 will have the same crystalorientation as the relaxed SiGe alloy layer 18 (which crystallographicorientation is determined by the second semiconducting layer 16). Hence,in this embodiment of the present invention, strained Si layer 20 hasthe same crystallographic orientation as the second semiconducting layer16.

A hard mask layer, i.e., pad stack, 22 is formed on an exposed uppersurface of the strained Si layer 20 utilizing a deposition process suchas, for example, chemical vapor deposition (CVD), plasma-enhancedchemical vapor deposition (PECVD), chemical solution deposition, atomiclayer deposition, or physical vapor deposition. Alternatively, the hardmask layer 22 can be formed utilizing a thermal oxidation, nitridationor oxynitridation process.

The hard mask layer 22 is composed of a dielectric material such as, forexample, an oxide, nitride, oxynitride or a stack thereof. In theembodiment shown in FIG. 1C, hard mask layer 22 comprises an oxide layer24 and a nitride layer 26. The thickness of the hard mask layer 22 mayvary depending on the composition of the mask material as well as thetechnique that was used in forming the same. Typically, the hard masklayer 22 has, an as deposited thickness, from about 5 to about 500 nm.

The hard mask layer 22 is then patterned by lithography and etching toprovide a patterned mask that is used in the present invention as anetch mask to remove an exposed portion of the strained Si layer 20, anunderlying portion of the relaxed SiGe alloy layer 18, an underlyingportion of the second semiconducting layer 16, and an underlying portionof the buried insulating layer 14 of the hybrid substrate 10, stoppingeither on an upper surface of the first semiconducting layer 12 orwithin the first semiconducting layer 12. The structure after patterntransfer and formation of opening 25 is shown, for example, in FIG. 1C.

The etching of the hard mask layer 22 and pattern transfer may beperformed utilizing a single etching process or multiple etching stepsmay be employed. The etching may include a dry etching process such asreactive-ion etching, ion beam etching, plasma etching or laser etching,a wet etching process wherein a chemical etchant is employed or anycombination thereof. In one preferred embodiment of the presentinvention, reactive-ion etching (RIE) is used in this step of thepresent invention to selectively remove the various layers exposing theunderlying first semiconducting layer 12.

Next, an optional spacer 27 can be formed in the opening 25 on theexposed sidewalls provided by the above processing steps. The optionalspacer 27 is formed by deposition and etching. The optional spacer 27can be comprised of an insulating material such as, for example, anoxide, nitride, oxynitride or any combination thereof. The optionalspacer 27 may be a single spacer, as shown, or it may comprise multiplespacers. FIG. IC shows the presence of optional spacers 27 in thestructure.

A regrown semiconductor material 28 is then formed on the exposedsurface of the first semiconducting layer 12. In accordance with thepresent invention, semiconductor material 28 has a crystallographicorientation that is the same as the crystallographic orientation of thefirst semiconducting layer 12. Although this regrown semiconductormaterial 28 will have the same surface orientation as the firstsemiconducting layer 12, it can be of a different semiconductor materialthan the first semiconducting layer 12.

The regrown semiconductor material 28 may comprise any semiconductormaterial, such as Si, strained Si, SiGe, SiC, SiGeC or combinationsthereof, which is capable of being formed utilizing a selectiveepitaxial growth method. The regrown material 28 can be strained orunstrained. In this embodiment, the regrown semiconductor material is anunstrained semiconductor material.

To achieve a high quality regrown semiconductor material 28, selectiveepitaxy is recommended where there is no polysilicon or amorphoussilicon formed on top of the patterned mask outside the openings 25. Toeliminate a facet formation during the epitaxy, the regrownsemiconductor material 28 can be grown, in some embodiments, higher thanthe patterned mask and then it is polished down to the patterned mask.

After forming the regrown semiconductor material 28, the structure issubjected to a conventional planarization process such CMP to providethe strained Si-containing hybrid substrate shown in FIG. 1D. As shown,the planarization step removes the patterned hard mask from thestructure providing a substantially planar strained Si-containing hybridsubstrate 10 in which the strained Si layer 20 is substantially coplanarto the regrown semiconductor material 28. The hybrid substrate shown inFIG. 1D has regions of different crystal orientations, i.e., thestrained Si layer 20 and the regrown semiconductor material 28, in whichsemiconductor devices can be formed.

Standard CMOS processing can be performed, including, for example,device isolation formation, well region formation, and gate regionformation. Specifically, after providing the structure shown, in FIG.1D, isolation regions, such as shallow trench isolation regions, aretypically formed so as to isolate the device regions from each other.

The isolation regions are formed utilizing processing steps that arewell known to those skilled in the art including, for example, trenchdefinition and etching; optionally lining the trench with a diffusionbarrier; and filling the trench with a trench dielectric such as anoxide. After the trench fill, the structure may be planarized and anoptional densification process step may be performed to densify thetrench dielectric.

Semiconductor devices, i.e., pFETs and nFETs, are formed on the exposedsemiconductor layers, i.e., the strained Si layer 20 and regrownsemiconductor material 28. In accordance with the present invention, thetype of device formed is dependent on the crystallographic orientationof the underlying semiconductor layer, i.e., the crystallographicorientation of the strained Si layer 20 and the crystallographicorientation of the regrown semiconductor layer 28. The pFETs and nFETsare formed utilizing standard CMOS processing steps that are well knownto those skilled in the art. Each FET includes a gate dielectric, a gateconductor, an optional hard mask located atop the gate conductor,spacers located on sidewalls of at least the gate conductor, andsource/drain diffusion regions. Note that the pFET is formed over thesemiconductor material that has a (110) or (111) orientation, whereasthe nFET is formed over a semiconductor surface having a (100) or (111)orientation.

FIGS. 2A-2D show a second embodiment of the present invention. In thisembodiment, as shown in FIG. 2D, the regrown semiconductor material 28comprises a recessed relaxed SiGe alloy layer. A strained Si layer 20 isformed atop the recessed relaxed SiGe material 28. In the secondembodiment, the strained Si layer 20 has the same crystallographicorientation as the regrown semiconductor material 28. Hence, since theregrown semiconductor material 28 is formed atop a portion of the firstsemiconducting layer 12 of a first crystallographic orientation, therecessed regrown semiconductor material 28 and the strained Si layer 20have the first crystallographic orientation.

FIG. 2A shows a hybrid substrate 10 that includes a first semiconductinglayer 12, a buried insulating layer 14 located on the firstsemiconducting layer 12 and second semiconducting layer 16 located inthe buried insulating layer 14. The hybrid structure 10 shown in FIG. 2Ais the same as that shown in FIG. 1A; therefore the above descriptionconcerning the various elements and processes used above apply equallyhere for this embodiment.

Next, the structure shown in FIG. 2B is provided by first forming a hardmask layer 22 comprising an oxide layer 24 and a nitride layer 26 atop asurface of the second semiconducting layer 16. An opening 25 is providedthat exposes a surface of the underlying first semiconducting layer 12.The opening 25 is formed by first patterning the hard mask layer 22 bylithography and etching. Optional spacers 27 are then formed asdescribed above.

A regrown semiconductor material 28 comprising a relaxed SiGe alloylayer is then formed by selective epitaxy on the exposed surface of thefirst semiconducting layer 12. The relaxed SiGe alloy layer (i.e.,regrown semiconductor material 28) can be planarized to the top surfaceof the patterned hard mask layer 22 if needed, and then it is recessedby utilizing a timed RIE step to provide the structure shown, forexample, in FIG. 2C. The depth of the recess may vary depending on thedesired thickness of the strained Si layer 20 to be subsequently formed.

In this embodiment of the present invention, the relaxed SiGe alloylayer, i.e., regrown semiconductor material 28, which is formed byepitaxy has the same crystallographic orientation as that of the firstsemiconducting layer 12.

Next, a strained Si layer 20 is formed by a conventional depositionprocess such as CVD or epitaxy, atop the recessed surface of the regrownrelaxed SiGe alloy layer 28. The patterned hard mask layer 22 is thenremoved from the structure via a planarization process providing thestrained Si-containing hybrid substrate shown in FIG. 2D. In thisembodiment, one of the device regions for forming CMOS devices is theexposed surface of the second semiconductor layer 16, while the otherdevice region is the strained Si layer 20. In this embodiment, thestrained Si layer 20 has the same crystallographic orientation as firstsemiconducting layer 12 since it is located atop an epitaxially regrownsemiconductor material 28. Isolation regions and CMOS devices asdescribed above can be formed on the structure shown in FIG. 2D.

The third embodiment of the present invention is slightly different fromthe first two embodiments mentioned above in that the process flowbegins with first providing the structure shown in FIG. 3A whichincludes a first semiconducting layer 12 in the form of a relaxed SiGealloy layer formed directly on a surface of a handle wafer 100. Thehandle wafer comprises any semiconducting or non-semiconductingsubstrate and the first semiconducting layer 12 is formed by adeposition process.

Next, the structure shown in FIG. 3A is bonded to a structure thatincludes a buried insulating layer 14 and a second semiconducting layer16 so as to provide the structure shown in FIG. 3B.

A patterned hard mask layer 22 comprising oxide layer 24 and nitridelayer 26 is then formed as described above and thereafter an openingthat extends down to the relaxed SiGe alloy layer, i.e., firstsemiconducting layer 12, is formed through the patterned hard mask layer22. A regrown semiconducting material 28 comprising a relaxed SiGe alloyis then regrown on the exposed first semiconducting layer 12 which alsocomprises a relaxed SiGe alloy layer providing the structure shown, inFIG. 3C.

The regrown semiconductor material 28 comprising the relaxed SiGe alloyis then recessed as described above and a strained Si layer 20 is formedthereon. The structure is then planarized providing the strainedSi-containing hybrid substrate shown in FIG. 3D.

FIGS. 4A-4E show a fourth embodiment of the present invention forforming a strained Si-containing hybrid substrate. The fourth embodimentof the present invention begins with providing the initial structureshown in FIG. 4A. The initial structure includes a first semiconductinglayer 12, a buried insulating layer 14 and a sacrificial secondsemiconducting layer 16′.

A SiGe alloy layer 50 that is thin (having a thickness of about 100 nmor less) is then formed atop the sacrificial second semiconducting layer16′ providing the structure shown in FIG. 4B. The SiGe alloy layer 50can be formed utilizing any conventional deposition process such as CVDor epitaxial growth.

The structure shown in FIG. 4B is then subjected to a thermal mixingstep. Specifically, the thermal mixing step is an annealing step that isperformed at a temperature which permits interdiffusion of Ge throughoutthe sacrificial second semiconductor layer 16′ and the SiGe alloy layer50 forming a relaxed SiGe alloy layer as the second semiconducting layer16 (See FIG. 4C). Note that an oxide layer (not shown) is formed atoplayer 16 during the annealing step. This oxide layer is typicallyremoved from the structure after the annealing step using a conventionalwet etch process wherein a chemical etchant such as HF that has a highselectivity for removing oxide as compared to SiGe is employed.

Specifically, the annealing step of the present invention is performedat a temperature from about 900° to about 1350° C., with a temperaturefrom about 1200° to about 1335° C. being more highly preferred.Moreover, the annealing step of the present invention is carried out inan oxidizing ambient which includes at least one oxygen-containing gassuch as O₂, NO, N₂O, ozone, air and other like oxygen-containing gases.The oxygen-containing gas may be admixed with each other (such as anadmixture of O₂ and NO), or the gas may be diluted with an inert gassuch as He, Ar, N₂, Xe, Kr, or Ne.

The annealing step may be carried out for a variable period of timewhich typically ranges from about 10 to about 1800 minutes, with a timeperiod from about 60 to about 600 minutes being more highly preferred.The annealing step may be carried out at a single targeted temperature,or various ramp and soak cycles using various ramp rates and soak timescan be employed.

The annealing step is performed under an oxidizing ambient to achievethe presence of a surface oxide layer which acts as a diffusion barrierto Ge atoms. Therefore, once the oxide layer is formed on the surface ofthe structure, Ge becomes trapped between buried insulating layer 14 andthe surface oxide layer. As the surface oxide increases in thickness,the Ge becomes more uniformly distributed throughout layers 16′ and 50but it is continually and efficiently rejected from the encroachingoxide layer. Efficient thermal mixing is achieved in the presentinvention when the heating step is carried out at a temperature fromabout 1200° to about 1320° C. in a diluted oxygen-containing gas.

It is also contemplated herein to use a tailored heat cycle which isbased upon the melting point of the SiGe layer. In such an instance, thetemperature is adjusted to tract below the melting point of the SiGelayer.

Following the annealing step which forms the second semiconducting layer16 that is comprised of a relaxed SiGe alloy by thermal mixing SiGealloy layer 50 and the sacrificial second semiconductor layer 16′, astrained Si layer 20 is formed atop the second semiconducting layer 16(i.e., the thermally mixed SiGe alloy layer). This structure is shown,for example, in FIG. 4C. The strained Si layer 20 is a thin layer havinga thickness of about 20 nm or less and it is formed by conventionaldeposition processes well known in the art. The strained Si layer hasthe same crystallographic orientation as the semiconducting layer 16that is formed via thermal mixing.

Next, the procedures used in forming the structure shown in FIG. 1Cabove are employed on the structure shown in FIG. 4C providing thestructure shown in FIG. 4D. Specifically, a patterned hard mask layer 22comprising oxide layer 24 and nitride layer 26 is first formed bydeposition and lithography, opening 25 is then formed by etching down tothe first semiconducting layer 12, optional spacers 27 are then formedby deposition and etching and regrown semiconductor material 28 that hasthe same crystallographic orientation as the first semiconducting layer12 is formed within the opening.

The strained Si-containing hybrid substrate shown in FIG. 4E is obtainedusing the processing steps described above in obtaining the structureshown in FIG. 1D which includes removal of the hard mask layer 22 andplanarization.

The fifth embodiment of the present invention is shown in FIGS. 5A-E.Unlike the previous embodiments described above, the final strainedSi-containing hybrid substrate shown in FIG. 5E has device regions thatare both SOI like since buried insulating layers are present beneath theregrown semiconductor material 28 and the second semiconductor layer 16.FIG. 5A shows the initial structure of this embodiment of the presentinvention. Specifically, the initial structure shown in FIG. 5A includesa handle wafer 100, bottom insulating layer 102, first sacrificialsemiconducting layer 12′ and SiGe alloy layer 50. The handle wafer 100may include any semiconductor or non-semiconductor substrate well knownin the art. Bottom insulating layer 102 is comprised of one of theinsulators mentioned above in regard to buried insulating layer 14. TheSiGe alloy layer 50 is formed as described above and that layertypically has a thickness of about 100 nm or less.

After providing the structure shown in FIG. 5A, the structure issubjected to the above described thermal mixing step providing thestructure shown in FIG. 5B. In this embodiment, the thermal mixing stepconverts the sacrificial first semiconducting layer 12′ and the SiGealloy layer 50 into a first semiconductor layer 12 that comprises athermally mixed and relaxed SiGe alloy. As shown, the structure includeshandle wafer 100, bottom insulating layer 102 and thermally mixed firstsemiconducting layer 12.

The structure shown in FIG. 5B is then bonded to another structure thatincludes a buried insulating layer 14 and a second semiconducting layer16 using the bonding process mentioned above. The resultant bondedstructure is shown, for example, in FIG. 5C.

A hard mask layer 22 comprising an oxide layer 24 and a nitride layer 26is then applied to a surface of the second semiconducting layer 16 shownin FIG. 5C and thereafter the hard mask layer 22 is patterned bylithography and etching. After patterning the hard mask layer 22, anopening that extends to a surface of the first semiconducting layer 12is formed by etching. Optional spacers 27 are then formed in the openingand regrown semiconductor material 28 comprising a SiGe alloy is grownon the exposed surface of the first semiconducting layer 12. Thestructure is then subjected to a planarization process which stops atopa surface of nitride layer 26. The resultant structure that is formedafter the above processing steps have been performed is shown, forexample, in FIG. 5D. In this embodiment of the present invention, theregrown semiconductor material 28 has a crystallographic orientationthat is the same as the first semiconducting layer 12.

FIG. 5E shows the structure that is formed after the regrownsemiconductor material 28 has been recessed, deposition of a strained Silayer 20 on the recessed regrown semiconductor material 28 and removalof the patterned hard mask layer 22 including the nitride layer 26 andthe oxide layer 24.

Reference is now made to FIGS. 6A-6D which illustrate a sixth embodimentof the present invention. In the sixth embodiment of the presentinvention, all the device areas of the hybrid substrate include strainedSi that has different crystallographic orientations.

FIG. 6A shows the initial hybrid substrate 10 that is employed in thepresent invention. As shown, the hybrid substrate 10 includes a firstsemiconducting layer 12, a buried insulating layer 14 located on thefirst semiconducting layer 12, and a second semiconducting layer 16located on the buried insulating layer 14. The elements of the hybridsubstrate 10 shown in FIG. 6A have been described above as well as theprocesses that are used in forming the same.

A relaxed SiGe alloy layer 18 is then formed on a surface of the secondsemiconducting layer 16 by an epitaxial growth method and thereafter afirst strained Si layer 20 is formed atop the relaxed SiGe layer 18. Thestructure including the relaxed SiGe alloy layer 18 and the firststrained Si layer 20 is shown, for example, in FIG. 6B.

After providing the structure shown in FIG. 6B, a hard mask layer 22comprising oxide layer 24 and nitride layer 26 is applied to a surfaceof the first strained Si layer 20 shown in FIG. 6B and thereafter thehard mask layer 22 is patterned by lithography and etching. Afterpatterning the hard mask layer 22, an opening that extends to a surfaceof the first semiconducting layer 12 is formed by etching. Optionalspacers 27 are then formed in the opening and regrown semiconductormaterial 28 comprising a relaxed SiGe alloy is grown on the exposedsurface of the first semiconducting layer 12. The structure is thensubjected to a planarization process which stops atop a surface ofnitride layer 26. The resultant structure that is formed after the aboveprocessing steps have been performed is shown, for example, in FIG. 6C.In this embodiment of the present invention, the regrown semiconductormaterial 28 has a crystallographic orientation that is the same as thefirst semiconducting layer 12

FIG. 6D shows the structure that is formed after the regrownsemiconductor material 28 has been recessed, deposition of a secondstrained Si layer 21 on the recessed semiconductor material 28 andremoval of the patterned hard mask layer 22 including the nitride layer26 and the oxide layer 24. In the strained Si-containing hybridsubstrate shown in FIG. 6D, the CMOS devices are formed on strained Silayers 20 and 21 that have different crystallographic orientations.

The seventh of the present invention will now be described in greaterdetail by referring to FIGS. 7A-7D. The seventh embodiment of thepresent invention begins with providing the structure shown in FIG. 7A.The structure shown in FIG. 7A comprising a handle wafer 100, and arelaxed SiGe layer as the first semiconducting material 12 formed atopthe handle wafer 100. The relaxed SiGe layer is formed via an epitaxialgrowth process that is well known to those skilled in the art.

The structure shown in FIG. 7A is then bonded to another structure thatincludes a buried insulating layer 14 and a second semiconducting layer16. The bonding is performed utilizing the bonding mentioned above. Thestructure that is formed after the bonding step is shown, for example,in FIG. 7B.

Next, a relaxed SiGe alloy layer 18 is formed via epitaxy on an exposedsurface of the second semiconducting layer 16 and then a first strainedSi layer 20 is formed atop the relaxed SiGe alloy layer 18. A hard masklayer 22 comprising oxide layer 24 and nitride layer 26 is applied to asurface of the first strained Si layer 20 and thereafter the hard masklayer 22 is patterned by lithography and etching. After patterning thehard mask layer 22, an opening that extends to a surface of the firstsemiconducting layer 12, i.e., relaxed SiGe layer, is formed by etching.Optional spacers 27 are then formed in the opening and regrownsemiconductor material 28 comprising a relaxed SiGe alloy is grown onthe exposed surface of the first semiconducting layer 12. The structureis then subjected to a planarization process which stops atop a surfaceof nitride layer 26. The resultant structure that is formed after theabove processing steps have been performed is shown, for example, inFIG. 7C. In this embodiment of the present invention, the regrown SiGealloy 28 has a crystallographic orientation that is the same as thefirst semiconducting layer 12.

FIG. 7D shows the structure that is formed after the regrown relaxedSiGe alloy layer 28 has been recessed, deposition of a second strainedSi layer 21 on the recessed regrown semiconductor material 28 andremoval of the patterned hard mask layer 22 including the nitride layer26 and the oxide layer 24. In the strained Si-containing hybridsubstrate shown in FIG. 7D, the CMOS devices are formed on strained Silayers that have different crystallographic orientations.

FIGS. 8A-8E show an eighth embodiment of the present invention. In thisembodiment, the structure shown in FIG. 8A is first provided. Thestructure shown in FIG. 8A includes handle wafer 100, bottom insulatinglayer 102, first sacrificial semiconducting layer 12′, and SiGe alloylayer 50. The SiGe alloy layer 50 is grown on the surface of the firstsacrificial semiconducting layer 12′ epitaxially.

The structure shown in FIG. 8A is then subjected to the thermal mixingstep described above which forms a first semiconducting layer 12comprising a thermally mixed relaxed SiGe layer on the bottom insulatinglayer 102. The resultant structure that is formed after the thermalmixing step is shown, for example, in FIG. 8B.

The structure shown in FIG. 8B is the bonded to a second structure thatincludes buried insulating layer 14 and second semiconducting layer 16.The bonding is performed as described above. The bonded structure isshown in FIG. 8C.

A relaxed SiGe alloy layer 18 and a first strained Si layer 20 is thenformed atop the surface of the second semiconducting layer 16. A hardmask layer 22 comprising oxide layer 24 and nitride layer 26 is appliedto a surface of the first strained Si layer 20 and thereafter the hardmask layer 22 is patterned by lithography and etching. After patterningthe hard mask layer 22, an opening that extends to a surface of thethermally mixed relaxed first semiconducting layer 12 is formed byetching. Optional spacers 27 are then formed in the opening and regrownsemiconductor material 28 comprising a relaxed SiGe alloy is grown onthe exposed surface of the first semiconducting layer 12 that comprisesthermally mixed and relaxed SiGe. The structure is then subjected to aplanarization process which stops atop a surface of nitride layer 26.The resultant structure that is formed after the above processing stepshave been performed is shown, for example, in FIG. 8D. In thisembodiment of the present invention, the regrown SiGe alloy 28 has acrystallographic orientation that is the same as the thermally mixedrelaxed SiGe layer 12.

FIG. 8E shows the structure that is formed after the regrown relaxedSiGe alloy layer 28 has been recessed, deposition of a second strainedSi layer 21 on the recessed regrown semiconductor material 28 andremoval of the patterned hard mask layer 22 including the nitride layer26 and the oxide layer 24. In the strained Si-containing hybridsubstrate shown in FIG. 8E, the CMOS devices are formed on strained Silayers that have different crystallographic orientations.

FIGS. 9A-9E shows the processing steps that are employed in a ninthembodiment of the present invention. FIG. 9A shows an initial structurethat includes first semiconducting layer 12, buried insulating layer 14,and a second sacrificial semiconducting layer 16′.

A SiGe layer 50 is then formed atop the second sacrificialsemiconducting layer 16′ by epitaxy. The SiGe layer 50 that is formedhas the same crystallographic orientation as the second sacrificialsemiconducting layer 16′. The SiGe alloy layer 50 has a thickness ofabout 100 nm or less. The resultant structure including the SiGe alloylayer 50 is shown in FIG. 9B.

Next, the structure shown in FIG. 9B is subjected to the above describedthermal mixing step so as to form a second semiconducting layer 16 thatcomprises a thermally mixed relaxed SiGe alloy on the buried insulatinglayer 14. A first strained Si layer 20 is then formed atop the secondsemiconducting layer 16. The resultant structure including the thermallymixed relaxed SiGe layer 16 and the strained Si layer 20 is shown inFIG. 9C.

A hard mask layer 22 comprising oxide layer 24 and nitride layer 26 isapplied to a surface of the strained Si layer 20 shown in FIG. 9C andthereafter the hard mask layer 22 is patterned by lithography andetching. After patterning the hard mask layer 22, an opening thatextends below a surface of the first semiconducting layer 12 is formedby etching. Optional spacers 27 are then formed in the opening andregrown semiconductor material 28 comprising a relaxed SiGe alloy isgrown on the exposed surface of the first semiconducting layer 12. Thestructure is then subjected to a planarization process which stops atopa surface of nitride layer 26. The resultant structure that is formedafter the above processing steps have been performed is shown, forexample, in FIG. 9D. In this embodiment of the present invention, theregrown SiGe alloy 28 has a crystallographic orientation that is thesame as the first semiconducting layer 12.

FIG. 9E shows the structure that is formed after the regrownsemiconductor material 28 has been recessed, deposition of a secondstrained Si layer 21 on the recessed regrown semiconductor material 28and removal of the patterned hard mask layer 22 including the nitridelayer 26 and the oxide layer 24. In the strained Si-containing hybridsubstrate shown in FIG. 9E, the CMOS devices are formed on strained Silayers that have different crystallographic orientations.

The tenth embodiment of the present invention is shown in FIGS. 10A-10F.This embodiment of the present invention, see FIG. 10A, begins bygrowing a SiGe layer as the first semiconducting layer 12 on the surfaceof a handling wafer 100. This structure is bonded to a structure thatincludes a buried insulating layer 14 and a second sacrificialsemiconducting layer 16′. The bonding is performed as described above.The resultant structure is shown in FIG. 10B.

A SiGe layer 50 having the same crystallographic orientation as that ofthe second sacrificial semiconducting layer 16′ is then formed atop thesecond sacrificial semiconducting layer 16′ providing the structureshown, for example, in FIG. 10C. The structure shown in FIG. 10C is thensubjected to the above described thermal mixing process forming athermally mixed relaxed SiGe alloy layer as the second semiconductinglayer 12 on a surface of the buried insulating layer 14.

A first strained Si layer 20 is then formed atop the thermally mixedsecond semiconducting layer 16 providing the structure shown in FIG.10D. The strained Si layer 20 has the same crystallographic orientationas that of the second semiconducting layer 16.

A hard mask layer 22 comprising oxide layer 24 and nitride layer 26 isapplied to a surface of the strained Si layer 20 shown in FIG. 10D andthereafter the hard mask layer 22 is patterned by lithography andetching. After patterning the hard mask layer 22, an opening thatextends to a surface of the first semiconducting layer 12 is formed byetching. Optional spacers 27 are then formed in the opening and regrownsemiconductor material 28 comprising a relaxed SiGe alloy is grown onthe exposed surface of the first semiconducting layer 12. The structureis then subjected to a planarization process which stops atop a surfaceof nitride layer 26. The resultant structure that is formed after theabove processing steps have been performed is shown, for example, inFIG. 10E. In this embodiment of the present invention, the regrownsemiconductor material 28 has a crystallographic orientation that is thesame as the first semiconducting layer 12.

FIG. 10F shows the structure that is formed after the regrownsemiconductor material 28 has been recessed, deposition of a secondstrained Si layer 21 on the recessed semiconductor material 28 andremoval of the patterned hard mask layer 22 including the nitride layer26 and the oxide layer 24. In the strained Si-containing hybridsubstrate shown in FIG. 10F, the CMOS devices are formed on strained Silayers that have different crystallographic orientations.

The eleventh embodiment of the present invention will now be describedin detail by referring to FIGS. 11A-11G. FIG. 11A shows an initialstructure that includes handle wafer 100, bottom insulating layer 102,first sacrificial semiconducting layer 12′, and SiGe alloy layer 50. TheSiGe alloy layer 50 is formed via an epitaxial growth method.

The structure shown in FIG. 11A is then subjected to the above describedthermal mixing process whereby the first semiconducting layer 12 isformed. The structure after thermal mixing is shown in FIG. 11B.

The structure of FIG. 11B is then bonded to another structure thatincludes buried insulating layer 14 and second sacrificialsemiconducting layer 16′ to provide the structure shown in FIG. 11C. Thebonded structure of FIG. 11C is formed utilizing the aforementionedbonding process.

A thin SiGe alloy layer 50 having a thickness of about 100 nm or less isthen formed on the second sacrificial semiconducting layer 16′ providingthe structure shown in FIG. 11D. This structure containing SiGe alloylayer 50 is then subjected to another thermal mixing step whereby theSiGe alloy layer 50 and the second sacrificial semiconducting layer 16′are thermally mixed and converted into the second semiconductingmaterial 16. A first strained Si layer 20 is then formed on thethermally mixed second semiconducting layer 16. The resultant structurethat is formed after these two steps have been performed is shown inFIG. 11E.

A hard mask layer 22 comprising oxide layer 24 and nitride layer 26 isapplied to a surface of the first strained Si layer 20 shown in FIG. 11Eand thereafter the hard mask layer 22 is patterned by lithography andetching. After patterning the hard mask layer 22, an opening thatextends to a surface of the first semiconducting layer 12 is formed byetching. Optional spacers 27 are then formed in the opening and regrownsemiconductor material 28 comprising a relaxed SiGe alloy is grown onthe exposed surface of the first semiconducting layer 12. The structureis then subjected to a planarization process which stops atop a surfaceof nitride layer 26. The resultant structure that is formed after theabove processing steps have been performed is shown, for example, inFIG. 11F. In this embodiment of the present invention, the regrownsemiconductor 28 has a crystallographic orientation that is the same asthe first semiconducting layer 12.

FIG. 11G shows the structure that is formed after the regrownsemiconductor material 28 has been recessed, deposition of a secondstrained Si layer 21 on the recessed regrown semiconductor material 28and removal of the patterned hard mask layer 22 including the nitridelayer 26 and the oxide layer 24. In the strained Si-containing hybridsubstrate shown in FIG. 11G, the CMOS devices are formed on strained Silayers that have different crystallographic orientations.

While the present invention has been particularly shown and describedwith respect to preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formsand details may be made without departing from the spirit and scope ofthe present invention. It is therefore intended that the presentinvention not be limited to the exact forms and details described andillustrated, but fall within the scope of the appended claims.

1. A method of fabricating a strained Si-containing hybrid substratecomprising the steps of: providing a hybrid substrate comprising a firstsemiconducting layer of a first crystallographic orientation, a buriedinsulating layer located on a surface of the first semiconductor layerand a second semiconducting layer of a second crystallographicorientation which is different from the first crystallographicorientation located on said buried insulating layer; providing anopening the extends to a surface of the first semiconducting layer; andregrowing a semiconductor material on said first semiconducting layer insaid opening, said semiconductor material having the firstcrystallographic orientation, with the proviso that a strained Si layeris formed overlying at least one of the second semiconducting layer orthe regrown semiconductor material, said Si layer having acrystallographic orientation that matches that of said underlying secondsemiconducting layer or the regrown semiconductor material.
 2. Themethod of claim 1 wherein the providing the hybrid substrate comprises alayer transfer technique and bonding.
 3. The method of claim 2 whereinthe bonding is performed by bringing two semiconductor wafers intointimate contact with each other, optionally applying an external forceto the contacted wafers, and heating.
 4. The method of claim 1 whereinat least one of the first or second semiconducting layers is formed viaa thermal mixing process which converts a sacrificial semiconductinglayer and an overlying SiGe alloy layer into a thermally mixed relaxedSiGe alloy layer.
 5. The method of claim 4 wherein both the first andsecond semiconducting layers are formed by said thermal mixing.
 6. Themethod of claim 5 wherein said thermal mixing is performed in anoxygen-containing ambient at a temperature from about 900° C. to about1350° C.
 7. The method of claim 1 wherein prior to providing saidopening a relaxed SiGe alloy layer and a strained Si layer are formedatop the second semiconducting layer.
 8. The method of claim 1 whereinthe providing said opening comprising forming a patterned hard masklayer atop said hybrid substrate and etching.
 9. The method of claim 1wherein the regrown semiconductor is non-recessed after regrowth. 10.The method of claim 1 wherein the regrown semiconductor material isrecessed after regrowth and a strained Si layer is formed thereon. 11.The method of claim 1 wherein said strained Si layer is provided abovesaid second semiconducting layer.
 12. The method of claim 1 wherein saidstrained Si layer is provided above said regrown semiconductor material.13. The method of claim 1 wherein said strained Si layers are providedabove second semiconducting layer and above the regrown semiconductormaterial.
 14. The method of claim 1 wherein optional spacers are formedwithin said opening prior to regrowth.
 15. The method of claim 1 furthercomprising forming device isolation regions in said strainedSi-containing hybrid substrate.
 16. The method of claim 1 furthercomprising forming CMOS devices on said strained Si-containing hybridsubstrate.
 17. The method of claim 16 wherein the CMOS devices arenFETs, said nFETs are formed atop a strained Si layer having a (100)surface orientation